Holding tank support - 2007 Classic

[dznf0g]

It's too late for this year, but I have been considering installing holding tank and sewer pipe heaters so I don't necessarily have to rely on propane to prevent freeze. Can anyone tell me if the tanks are fully supported by the galvanized pans? Or are they fastened to the frame and the pan just contains the insulation.

I'd hate to have a surprise when loosening the pan bolts.

[wasagachris]

on my 73 the tanks sit inside the galvanized pans and the pans are riveted to the supports for the pans. I can imagine that the same process must apply to a 2007. How would a/s attach the plastic tanks to the frame? If you remove the supports for the galvanized pans the holdings tanks should come down with the pans.

[dznf0g]

Well, My old trailer's (SOB) tanks had molded flanges which bolted into the frame rails and an angle iron frame along the edges.(no pans...3 season trailer)
So, how do you support the tank so as not to stress the sewer lines while removing the pans?

[wasagachris]

when I re & re'd mine i removed the sewer lines first from the tanks and then removed the tanks from the pans. Of course it was easy for me because when I removed the tanks there was no floor in the trailer. Actually there was no trailer in the trailer either. The shell was sitting on sawhorses at the time.
If you disconnect the tank valves that should seperate the tanks from the rest of the sewer lines and you should be able to remove the lines to give you access room to remove the tanks. I'm assuming that you have or will be dropping the belly to do this.

[dznf0g]

No, the Classics have separate pans from the underbelly. The belly skin is in 2 separate halves, and the tanks hang several inches lower than the belly skin. Tank pans are galvanized and completely separate "compartments" not in any way connected to the belly skins. I don't want to remove the tanks. I just want to figure out how to drop the pans, with the tanks in place, affix the heaters to the bottom of the tanks, and slap the pans back in place.

Can that be done?

[wasagachris]

so the tanks are in the middle of the trailer with one belly skin in front and one in the rear? Where is the fresh water tank? I would support both tanks with jacks , undo the bolts and slowly lower the jacks ans observe what happens. I still think that the tanks just sit in the pans so you would have to disconnect all plumbing above the tanks. The toilet would have to come off and remove the screw in flange for the toilet. The drain line going in to the grey tank would have to be disconnected as well as all vent pipes attached to any tanks. Maybe someone with a 2007 will chime in and know how yours is set up.

[dznf0g]

Wasa,

I'm going from memory here, but yes, a rear belly pan extends from bumper to about 2 feet from the rear axle. then 2 galvanized pans. The rear one houses the black and gray and the front one houses the fresh water. then the belly skin resumes all the way to the front.

I don't have any pics, but I know there are some on the forum. I'll go huntin'.

[wasagachris]

I've installed the tank heaters you are thinking about. IIRC the installation instructions state not to cover over the heaters or they may overheat and fail. Contact the heater pad manufacturer and ask them about your plans. If you put them on the bottom of the tanks and then cover them with the insulation and the galvanized pans this may lead to problems. The pads are designed to be attached to the bottom of the tanks with the peel and stick application already applied to the pads. I do remember that the glue didn't hold well and I always added some aluminium foil tape to the edges to make sure they stayed on the tanks.

[dznf0g]

http://cdn.airforums.com/forums/atta...1&d=1283733094

Wasa,

Hope this works....never tried this before. The front tank with the spigot is the fresh tank, between the axles. Aft of the rear axle is the black and gray tanks, both in a single pan.

[dznf0g]

Originally Posted by wasagachris

I've installed the tank heaters you are thinking about. IIRC the installation instructions state not to cover over the heaters or they may overheat and fail. Contact the heater pad manufacturer and ask them about your plans. If you put them on the bottom of the tanks and then cover them with the insulation and the galvanized pans this may lead to problems. The pads are designed to be attached to the bottom of the tanks with the peel and stick application already applied to the pads. I do remember that the glue didn't hold well and I always added some aluminium foil tape to the edges to make sure they stayed on the tanks.

Wow, really. I wonder why. My waterbed heaters have spent 10 years and more of full time operation sandwiched between plastic/plywood and mattress without an issue.

I've even considered using waterbed heaters instead of RV tank heaters, but can't figure how to overcome the 12v travel problem. They are about 1/2 the cost of RV heaters.

[wasagachris]

The link worked. The pic is a little small but I can see what you mean. I just looked at the websites of 2 different manufacturers of tank heaters.
UltraHeat, Inc. - Home
JR Products
FAQ's for ultraheat state that they can be used in enclosed, insulated and forced air heated situations and claim protection down to -11 F. Amp draw is 4.1 amps DC for 25 gals, 9.9 amps DC for 40 gals and 11.8 amps DC for 60 gals or 9 amps DC/.094 amps AC combo unit 60 gals or 1.68 amps AC for 60 gals. Ultraheat also makes pipe heat and elbow heat pads.
JR products claim protection down to -5 F for sewer and 0 F for water.
Ultraheat wholesale price is only $30 more.

Andy where are you now. Inland Andy knows how each and every a/s that ever built was made.
Are you planning to heat fresh water tank also?
I still think galvanized box holds up tanks and a lot of removal needed to drop box and tank.

[dznf0g]

Yes, all three tanks.

[wasagachris]

Black tank 39 gals & grey tank 37 gals: Model 1200 DC powered (9.9 amps) or model 4200 AC (1.37 amps) or model 3600 AC/DC (9/.094 amps).
Fresh water tank 54 gals: model 2400 DC (11.8 amps) or model 4800 AC (1.68 amps).
DC models for on road use and AC models for use with shore power. DC models are hard wired to fuse panel and AC models just plug in to receptacles.
Lets say you use DC models the total amp draw would be 31.6 amps and would require three seperate fuses to run them all. If you use combo units on waste tanks and the only available AC model on fresh then amp draw would be 3.56 amps AC and 18 amps DC. The AC units could be on one AC circuit and two fuses for the DC.
If you also wanted to protect drain elbows and pipes and the fresh water pipe there are models available for that. This would also draw more amperage.
When do you expect to use them? On the road or set up in a park with shore power?

[2airishuman]

Originally Posted by dznf0g

...Can anyone tell me if the tanks are fully supported by the galvanized pans? Or are they fastened to the frame and the pan just contains the insulation. I'd hate to have a surprise when loosening the pan bolts.

they are almost entirely supported by the galvanized pans...

don't start to loosen pan bolts with anything but EMPTY tanks.

they can be supported with jack stands and timber,

but getting the pan off completely is a 2-3 person dance,

and best done with the stream UP on jack stands to provide more work space.
__________

basically the tanks, outer plumbing, drains, insulation and belly pan are assembled...

with the frame INVERTED, then the hole mess is flipped over 4 finishing/fitting.

so working from below after the fact is problematic, but not impossible.
__________

the notion of adding tank heaters is like trying to solve a problem that doesn't exist...

with a solution that doesn't really address the areas at risk.
__________

the forced air furnace only provides warm air to one tank proximally.

as a result of 'leaking' this air may circulate (escape) incidentally near the other tanks.

simply by 'enclosing' the tanks there is adequate heat in a WARM stream to minimize tank freezing.

a FULL fresh tank has adequate thermal mass to resist freezing, while a near empty tank is at risk.

improving the insulation and external ENCLOSURE for the tanks would be useful.
_________

the 12v heating elements available today will quickly drain the batteries,

without providing ANY warmth to the pipes/plumbing that are at risk in frigid temps.

most of the plumbing is inside the stream, so maintain a cabin temp above freezing and the system is mostly protected.

trying to use 12v tanks elements AND the furnace fan together would simply overtax the dc system.

it's also useful to leave the water heater ON or at least turn it ON every 2-3 hours.
__________

having stored the stream at ZERO fully prep'd for travel (with water) and having camped/towed in wind chills of 20-40 below zero...

the main objective is to keep the interior warm and let that heat diffuse into the structural parts.

insulating the ceiling vents/skylights and sealing the ENTRY door reduce heat loss.

adding bubble foil (inside) to the windows and vista views simply leads to excessive ICING inside.
__________

the at risk plumbing bits are all tiny appendages that are externally exposed and beyond heating with pads OR the furnace.

the shower trap (in some models), and the low water line drain valves and fresh tank drain valve.

the analogy is that fingers, noses and toes are the primary areas 4 frostbite.

so consider covering the drain valves with bubble foil and aluminum tape and temporarily covering other outside bits.

cheers
2air'

[Aage]

To augment what has already been said (and as it appears that the newer tanks are held in using a similar method to the older ones) here is the 1977 (rear bath) instructions and exploded view:

[dznf0g]

Originally Posted by wasagachris

Black tank 39 gals & grey tank 37 gals: Model 1200 DC powered (9.9 amps) or model 4200 AC (1.37 amps) or model 3600 AC/DC (9/.094 amps).
Fresh water tank 54 gals: model 2400 DC (11.8 amps) or model 4800 AC (1.68 amps).
DC models for on road use and AC models for use with shore power. DC models are hard wired to fuse panel and AC models just plug in to receptacles.
Lets say you use DC models the total amp draw would be 31.6 amps and would require three seperate fuses to run them all. If you use combo units on waste tanks and the only available AC model on fresh then amp draw would be 3.56 amps AC and 18 amps DC. The AC units could be on one AC circuit and two fuses for the DC.
If you also wanted to protect drain elbows and pipes and the fresh water pipe there are models available for that. This would also draw more amperage.
When do you expect to use them? On the road or set up in a park with shore power?

It will be next year before I think about an install.
I would put AC on black and gray, as I would not run the road with anything in them; AC on dump outlets; and probably 12V on fresh. It would be nice if they made units with both 12V and 120V circuits in them, for flexibility of usage need.

I'll have to noodle how I intend to winter camp, before I make final decisions.

[dznf0g]

Thanks, 2air,

So you are saying that even at sub-zero temps the furnace will keep the fluids in the tank from freezing?

My biggest concern is the valve/drain assemblies. Are you indicating that they still work well with just a reflectix wrap? Even when traveling all day? Are you running the furnace while you travel?

I think your tank setup is like mine. Is the routing of "warm" forced air like this:
1) duct terminates in fresh water compartment
2) flows (somewhat) through frame crossmember between the 2 pans, into the black/gray compartment.....of course leaking out all along the way.

Did you perform additional insulating/sealing of the pans to try and "manage" flow of warm air and direct it's eventual exit (perhaps at the dump valve handles)?

[2airishuman]

yep, that's the basic layout/flow of the warm (one duct) furnace air on classics...

i have not altered the oem pan/insulation it is simply too much trouble and risk gaining access.

the entire tank pan could be wrapped externally with bubble foil and aluminum tape (that should survive 1 winter season)

leaving the water heater ON gas provides a lot of warmth (and conducted heat) for not much effort.
__________

the external drain valves for the waste tanks can and will freeze.

depending on volume IN the tanks this seems to happen at about 20 degrees F.

of course they do thaw eventually, so my approach is to NOT use the dump valves until reaching a warmer location.

other folks dump a gallon of pink stuff into each EMPTY tank and hope some of it reaches the valves.

the freshwater feed line to the pump may freeze or get slushy.

this happened while towing once, at 10-20 degrees for a daytime HIGH.

again reaching warmer locations solves this issue too.

i do use the furnace when towing, primarily if the daytime highs are 30 or less.

taping the entry door (inside or outside) helps a lot.

since these trailers ALL leak air badly, one can use a LOT of lp gas towing in frigid weather.

2x40 lbs and a 20 lb spare in the truck.

keep furnace set to 40-44 as night time approaches if still on the road,

and once parked crank the furnace heat up to 65 (boondocking) or include space heaters IF connected to juice.

a lot depends on the winter camping goal.

IF simply taking a weekend trip it might be best to winterize the plumbing with pink stuff.

then carry drinking water, skip the shower and use a porta pot or trash bag in the toilet bowl...

IF traveling cross country with the occasional frozen night, use all systems on 'self contained' mode.
_________

full time winter living is an entirely different beast and pipe wrap heaters, skirting or other residential tricks are needed.
_________

there are several old threads on towing in d' polar belt or occasional winter trips.

http://www.airforums.com/forums/f459...ing-49725.html

http://www.airforums.com/forums/f462...her-27228.html

http://www.airforums.com/forums/f462...ing-19662.html

cheers
2air'

[dznf0g]

Thanks, again 2air,

Maybe all I'll do is reflectix the pans, maybe seal up extraneous air leaks in pans to try and direct airflow more positively.

Perhaps an AC dump pipe heater and wrap that area as well as the fresh water drain.

[Hoosierdaddy]

Hey Aage,
Where could I find a drawing of the tank setup in my 69 Overlander??? I'm having to replace rusted out supports and galvanized skin.
Thanks,
Dean